Question

If the threshold wavelength of a metal is in the green light region, then which of the following radiation cannot cause emission of electrons from metal?

• A. Blue
• B. Indigo
• C. Violet
• D. Orange

Hint:

In the photoelectric effect, radiation with a wavelength shorter than the threshold wavelength can cause electron emission. Radiation with longer wavelengths, like red or orange light, cannot cause electron emission.

Answer 1

The Correct Option is D

The threshold wavelength corresponds to the minimum wavelength of light that can cause the emission of electrons from a metal surface (photoelectric effect). Radiation with a wavelength shorter than the threshold wavelength has sufficient energy to knock electrons off the surface. - Blue, Indigo, Violet, and UV all have shorter wavelengths than green light, so they can cause the emission of electrons. - Orange light has a longer wavelength than green light, so it does not have enough energy to cause electron emission. Thus, Orange light cannot cause emission of electrons.